How many chest radiographs prompt changes in therapy for home mechanical ventilation (HMV) patients admitted to the hospital for pneumonia? Since HMV patients are more complex than those with simple community-acquired pneumonia, it is not known how many chest radiographs are needed for optimal management. To answer this, we reviewed all HMV patients admitted for pneumonia from July 2007 through June 2008. Demographic data, sequential chest radiographs, and changes in respiratory orders within 24 hours were recorded Childrens Hospital Los Angeles followed 180 HMV patients. Twenty-eight patients (16%) were admitted (36 readmissions). Twenty-five of these patients (90%) required full-time HMV Eighteen patients (64%) had the diagnosis of chronic lung disease. On discharge, 24 patients (66%) had residual pneumonia on chest radiographs. We conclude that HMV patients averaged five chest radiographs per pneumonia admission. Two-thirds of the chest radiographs did not prompt subsequent changes in respiratory therapy. More than one-third of the chest radiographs found no interval changes. The majority of discharges were not contingent on resolution of the chest radiographs findings. We speculate that the frequency of chest radiographs could be less and that chest radiographs were not the sole predictors of changes in respiratory treatment or the decision to discharge.